Caption: Solar power plant. Aerial photograph of Nevada Solar One, a 64 megawatt capacity power plant located in Boulder City near Las Vegas, Nevada, USA. It is estimated to produce 134 million kilowatt hours of electricity per year. More than 180,000 parabolic mirrors track the Sun across the sky and focus the Sun's rays onto tubes containing a transfer fluid, heating it to 390 degrees Celsius. The fluid passes through a heat exchanger, which is used to boil water for steam turbine generators.